Automated optical inspection (AOI) image inspection systems have high speed and high accuracy. AOI systems inspect by using machine visual technology and thus may replace manual inspection. In industry manufacturing process, AOI systems may sense the surface status of the finished product and then inspect the defects such as foreign matter or abnormal pattern by computer image processing algorithm.
However, when tradition AOI systems inspect defects, leakage (referring the situation that the defects are not inspected and thus failed samples are wrongly judged as good samples) or overkill (referring the situation that good samples are wrongly judged as failed samples) may occur. As for leakage or overkill, in tradition, manual inspection is relied to improve the accuracy rate.
Further, in tradition AOI technology, the sample (for example, the wafer) will be fed into training characteristic models, classification mode, defects classification and the like procedures. Therefore, it is difficult to achieve fast production change in tradition AOI technology.